1. Field of the Invention
This invention relates to a prosthetic filler for a living body (hereinafter, simply referred to as “prosthetic filler”) which is mainly used for medical and dental purposes, and a method of manufacturing the prosthetic filler.
2. Description of the Prior Art
In medical and dental fields, calcium phosphate is used as a material for artificial bones and bone prostheses. For example, when a defect is produced in a bone due to bone fracture, bone tumor or the like, the bone defect site is restored or repaired by using a bone prosthesis made of calcium phosphate.
As for such a bone prosthesis made of calcium phosphate, a bone prosthesis of block type and a bone prosthesis of granule type are known. Examples of the block type bone prosthesis are disclosed in Japanese Patent Laid-open No. Hei 8-182753, Japanese Patent Laid-open No. Hei 11-128336, Japanese Patent Laid-open No. Hei 11-244373, Japanese Patent Laid-open No. Hei 11-276510, and Japanese Patent Laid-open No. 2000-189510, and the like.
However, the block type bone prosthesis needs to be formed into a shape of a bone defect site by using a handpiece or the like at an operation site, and thus use of the block type bone prosthesis involves troublesomeness.
Further, it is difficult to use the block type bone prosthesis in a case where the shape of the bone defect site is complicated or in a case where the operation must be performed quickly. In addition to this, the block type bone prosthesis is not suitable for restoring a defect of soft tissue.
On the other hand, since the granule type bone prosthesis has flexibility in shape due to its granular form, it is possible to restore a bone defect site only by pouring it into the site. For this reason, use of such a granule type bone prosthesis makes it possible to perform an operation smoothly and speedily.
However, when the bone prosthesis is constituted from calcium phosphate granules only, there is a drawback that such a bone prosthesis is difficult to handle or use at the operation site, that is handlability thereof at the operation site is lowered. For example, there is a case that when the granule type bone prosthesis is to be filled into a bone defect site, a part of the granules is spilled and it is dissipated to irrelevant portions other than the bone defect site. Also, there is a case that a part of the granules filled in the bone defect site will be dissipated out of the bone defect site after the operation.
In order to solve these problems, a bone prosthesis having improved handlability at the operation site has been developed, which is disclosed in Japanese Patent Laid-open No.Hei 3-162863, for example. In this bone prosthesis, calcium phosphate granules are kneaded with polymeric material in order to improve handlability thereof. However, this bone prosthesis has a problem in that it is liable to be deteriorated, and thus it is not suitable for storage for a long period of time.